That's a serious question and deserves a serious answer. Let's compare the Bofors to the two different 155mm howitzers the USA uses.

The current towed 155mm howitzer is the M777, built by the Brits.http://en.wikipedia.org/wiki/M777_howitzer

It weighs 7,500 Lbs, is air transportable by CH47 or Osprey, has a max range of 24KM

The Bofors Haubits77A is the one in the video. http://en.wikipedia.org/wiki/Haubits_FH77

It weighs 25,000 lbs and has a range of 21KM

The current US 155mm self propelled howitzer is the M109A6 Paladin. http://en.wikipedia.org/wiki/M109_howitzer

It's a different animal altogether.

What we can see is that the US has radically different ideas about the two different roles of Artillery in Armored vs light forces. We went for maximum mobility, including air mobility. The Swedes wanted to split the difference.

One thing that's pretty interesting is that the Wiki page for the M777 shows the time to emplace and displace. They can emplace the gun in 2 minutes 10 seconds, fire the gun, and then have it hooked up to the truck and drive away 2 minutes and 23 seconds later. That's pretty amazing. Shoot and scoot is important in fast moving advances.

all that silly walking is "british drill" carried to the extreme. note also that the announcer is speaking "inglish" as opposed to english. same thing you get in phone calls from indian based phone "help" call centers, and they get very indignant when you cannot understand them.